The PDF from the TurboTax online editions can be opened by any PDF compatible program, such as Adobe Reader.
The tax data file which has a file extension of .taxyyyy where yyyy is the tax year, eg .tax2019 for tax year 2019 can only be opened by the TurboTax software for that tax year.
To access your current or prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on Download/print return (PDF) or Download .tax file
